Conventionally, there has been known a wireless charging system that charges a storage battery mounted on a vehicle using a power supply apparatus on the ground. In the wireless charging system, when power is supplied without a power supply coil and a power receiving coil being precisely positioned, a leakage magnetic field and unnecessary radiation increase. In this case, there is a problem of not being able to secure safety, for example, due to the malfunction of a pacemaker caused thereby.
For the problem mentioned above, there has been known a wireless charging system that starts charging after guiding a vehicle to a power supply section (e.g., Patent Literature (hereinafter, referred to as “PTL 1”)). PTL 1 discloses that, when a vehicle is driven for parking at a position where a power receiving section of the vehicle faces a power supply section on the ground, the image of a positioning marker at the rear of a parking space is picked up with an onboard camera and the picked-up image is displayed on a display section to thereby guide the vehicle to the most appropriate position. A transmission section at the rear of the parking space transmits a reference position signal after the parking of the vehicle. Then, the power supply section starts supplying power when the reception level of the reference position signal received by a reception section of the vehicle is equal to or greater than a predetermined level.